1. Field of the Invention
The present invention broadly relates to image projection systems and, more particularly, is concerned with an optical arrangement for stabilizing the projection of an image on a viewing screen such that vibratory movement of a platform supporting the screen does not affect the position of the image with respect to the screen.
2. Description of the Prior Art
In conducting research on the effect of vibration on human vision, it has been the practice heretofore to place the image projector, viewing screen and the subject whose vision is being tested on a common vibratory platform. Such test setup was considered to be essential to produce test conditions which closely simulate the actual field environment.
One problem with this test setup has been the difficulty and high cost associated with providing an image projector that can withstand severe vibration while producing and maintaining an image at a stationary position on the screen as the screen undergoes vibration along with the platform and subject. Heretofore, mechanical solutions to this problem have been sought, being primarily directed along the lines of providing some type of vibration damping means for protecting the components of the image projector. However, these approaches have not met with significant success, and so a need still exists for a more practical and cost effective solution.